Isolation and characterization of nettle (Urtica dioica L.) seed proteins: Conversion of underutilized by-products of the edible oil industry into food emulsifiers

AKSOYLU ÖZBEK Z., Kawata K., Zhou H., Chung C., Park J. H., McClements D. J.

Food Chemistry, vol.456, 2024 (SCI-Expanded, Scopus) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 456
  • Publication Date: 2024
  • Doi Number: 10.1016/j.foodchem.2024.139878
  • Journal Name: Food Chemistry
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aerospace Database, Aquatic Science & Fisheries Abstracts (ASFA), BIOSIS, CAB Abstracts, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, EMBASE, Food Science & Technology Abstracts, Metadex, Veterinary Science Database, Civil Engineering Abstracts
  • Keywords: Alternative protein, Circular economy, Emulsion stability, Sustainability
  • Manisa Celal Bayar University Affiliated: Yes

Abstract

This study aimed to upcycle a byproduct of the edible oil industry, cold-pressed nettle seed meal (CPNSM), into a plant-based emulsifier, thereby increasing the sustainability of the food system. The protein content of the nettle seed protein (NSP) powder was 48.3% with glutamic acid (16.6%), asparagine (10.7%), and arginine (9.7%) being the major amino acids. NSPs had a denaturation temperature of 66.6 °C and an isoelectric point of pH 4.3. They could be used as emulsifiers to form highly viscous coarse corn oil-in-water emulsions (10% oil, 4% NSP). Nevertheless, 10-fold diluted emulsions exhibited rapid creaming under different pH (2–9), salt (0–500 mM NaCl) and temperature (>40 °C) conditions, but they were relatively stable to aggregation. Our findings suggest that NSPs could be used as emulsifiers in highly viscous or gelled foods, like dressings, sauces, egg, cheese, or meat analogs.